UART Serial Port Programming Chapter 4 UART Serial Port Programming

Serial vs. Parallel Data Transfer

Parallel In Serial Out

Serial In Parallel Out

Simplex, Half-, and Full-Duplex Transfers

Framing ASCII "A" (0x41)

MAX232

MAX233

RS232 Pins Pin Description 1 Data carrier detect (DCD) 2 Received data (RxD) 3 Transmitted data (TxD) 4 Data terminal ready (DTR) 5 Signal ground (GND) 6 Data set ready (DSR) 7 Request to send (RTS) 8 Clear to send (CTS) 9 Ring indicator (RI)

9-Pin Male Connector

DTE-DCE and DTE-DTE Connections

Null Modem Connection with Flow Control Signals

ST-Link-V2-1 in Nucleo ST Arm board

ST-Link-V2-1 in Nucleo ST Arm board

St-Link/V2 USART2-USB Port Connection

Partial list of USART Registers and their addresses

A Simplified Block Diagram of USART

RCC_CR (RCC Control Register) to showing the HSI Clock Source

RCC_CFGR (Clock Configuration Register) Clock Select Resgister bit assignment

Clock Generation for USART2

APB1ENR peripheral clock enable register (RCC_APB1ENR) Bit Assignments (Partial Listing)

BAUD (USART_BRR) Register

BAUD Rate Register (BRR) Values for Some Baud Rates using OVER=16 and clock of 16MHz.

BAUD Rate Register (BRR) Values for Some Baud Rates using OVER=8 and clock of 16MHz.

USART CR1 (Control 1 Register) bits definition (Partial Listing)

USART Control 2 (USART_CTR2) register (Partial Listing)

USART_DR, USART Data Register

Status Register (USART_SR)

GPIO_AFRL (GPIO Alternate Function Register Low)

GPIO_AFRH (GPIO Alternate Function Register High)

partial list of STM Arm Pins Used for USART (See Appendix B and Table 4-6)

GPIOx_MODER (GPIO Mode) for Direction Register (x=A, B, C,..)

Alternate Functions (AF) Pin Multiplexing for Port A in STM32F446 Arm Alternate Functions (AF) Pin Multiplexing for Port A in STM32F446 Arm. See Appendix B for other Ports. (See AF table for your device)